Physical Layer Protection Against Relay/Replay Attacks for Short-Range Systems

In response to the rise of crime in short-range communication systems, a novel method for authenticating co-located devices is presented. Our method, Channel Randomness Yields Secure Proximity (ChRYSP) exploits the fundamental properties of the wireless RF channel to protect against relay attacks and replay attacks - the two most common impersonation attacks in short-range communication systems. ChRYSP is based on the fact that two devices in close proximity - typically a couple of wavelengths - experience correlated fading on a received RF signal. ChRYSP is facilitated by the employment of a helper node and can be implemented by low-cost, narrowband transceivers. Numerical results demonstrate high accuracy in detecting both relay attacks and replay attacks.